TY - GEN
N2 - This thesis presents a new approach to modeling in finite element analysis (FEA) creased thin-film sheets such as those used for drag sails, as well as modeling the packaging behavior of coilable deployable booms. This is highly advantageous because these deployable space structures are challenging to test on the ground due to their lightweight nature and the effects of gravity and air resistance. Such structures are utilized in the space industry due to their low mass and ability to be packaged into a small volume during their launch into space. It is shown that removing the crease bending stiffness in creased sheets still allows the deployment behavior of a benchmark problem to be captured, including deployment forces and equilibrium configurations. In addition, folding creased sheets from a flat state into a packaged configuration can result in crease crumpling and excessive wrinkling. To avoid this the Momentless Crease Force Folding (MCFF) technique is developed. Further presented is the behavior of tape springs and Tubular Rollable and Coilable (TRAC) booms when coiled to radii greater than their natural bend radius. Under these conditions the booms can form multiple localized folds which may jam during boom deployment. Understanding this behavior is important for extending the use of these booms to large scale space structures such as orbital solar power stations. A useful analytical model is developed determining when the localized folds in a tape spring will bifurcate and is verified against simulation results. Additionally, a numerical model of the wrapping an isotropic tape spring around a hub with a radius greater than the localized fold radii is validated against physical experiments. This model is used to predict trends in the force required to fully wrap a tape spring around a given hub radii. Finally, when examining the coiling and uncoiling behavior of TRAC booms it was found that the tension force required to keep a TRAC boom tightly coiled is significantly less than the force required to initially coil the boom.
AB - This thesis presents a new approach to modeling in finite element analysis (FEA) creased thin-film sheets such as those used for drag sails, as well as modeling the packaging behavior of coilable deployable booms. This is highly advantageous because these deployable space structures are challenging to test on the ground due to their lightweight nature and the effects of gravity and air resistance. Such structures are utilized in the space industry due to their low mass and ability to be packaged into a small volume during their launch into space. It is shown that removing the crease bending stiffness in creased sheets still allows the deployment behavior of a benchmark problem to be captured, including deployment forces and equilibrium configurations. In addition, folding creased sheets from a flat state into a packaged configuration can result in crease crumpling and excessive wrinkling. To avoid this the Momentless Crease Force Folding (MCFF) technique is developed. Further presented is the behavior of tape springs and Tubular Rollable and Coilable (TRAC) booms when coiled to radii greater than their natural bend radius. Under these conditions the booms can form multiple localized folds which may jam during boom deployment. Understanding this behavior is important for extending the use of these booms to large scale space structures such as orbital solar power stations. A useful analytical model is developed determining when the localized folds in a tape spring will bifurcate and is verified against simulation results. Additionally, a numerical model of the wrapping an isotropic tape spring around a hub with a radius greater than the localized fold radii is validated against physical experiments. This model is used to predict trends in the force required to fully wrap a tape spring around a given hub radii. Finally, when examining the coiling and uncoiling behavior of TRAC booms it was found that the tension force required to keep a TRAC boom tightly coiled is significantly less than the force required to initially coil the boom.
T1 - Analysis of packaging and deployment of ultralight space structures
AU - Wilson, Lee L.,
AU - Pellegrino, S.
VL - 2017
N1 - Advisor and committee chair names found in the thesis' metadata record in the digital repository.
ID - 921726
KW - deployable
KW - numerical analysis
KW - solar sail
KW - space
KW - tape spring
KW - thin-film
KW - TRAC boom
KW - ultralight
TI - Analysis of packaging and deployment of ultralight space structures
LK - http://resolver.caltech.edu/CaltechTHESIS:05242017-230338904
UR - http://resolver.caltech.edu/CaltechTHESIS:05242017-230338904
ER -